Machine for bending scythe-snaths.



No. 728,890. PATENTED MAY 26.1903.

G. M. PENN.

MACHINE FOR BENDING SCYTHE S NATHS.

APPLICATION FILED MAR. 2a, 1903.

N MODEL. 48 I 9 I 19 30 2 o 30a 52 0 c o 37 39 20 o 63 34 34 v 3 22 t 1.5? 22 I 5 UNITED STATES Patented May 26, 1903.

PATENT OFFICE.

MACHINE FQR BE ome SCYTHE-SNATHS.

SPECIFICATION forming part of Letters Patent No. 728,890, dated May 26, 1903.

Application filed March 28, 1903.

T0 (0Z5 whom it may concern:

Be it known that I, l GEORGE ME RIHUE FENN, a citizen of the United States, residing atOharlotte, in the county of Eaton and State of Michigan, have invented a new and useful Machine for Bending Scythe-Snaths, of which the following is a specification.

This invention relates to certain improvements in machines for bending scythe-snaths, and particularly to that class of machines illustrated in Letters Patent granted to me on August 19, 1902, under No. 707,221.

The present invention relates more especially to improvements in the construction and method of supporting and operating the protective bands employed to prevent-splintering or breaking of the blank being operated upon, with a view of preventing premature movement of the arms employed to effect end pressure on the blank during the bending operation.

With this and other objects in view the invention consists in the novel construction and arrangement of parts hereinafter described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions,and minor details of construction may be made without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings, Figure 1 is a plan view of sufficient of a machine for bending scythe-snaths to illustrate the application of the invention thereto. Fig. 2 is a longitudinal sectional elevation of a portion of the machine on the line 2 2 of Fig. 1. Fig. 3 is a detail perspective view of a portion of the machine, illustrating the improved connections for the support of the protective bands.

Similar numerals of reference designate corresponding parts in all the figures of the drawings. i

In the machine forming the subject of the hereinbefore mentioned Letters Patent a suitable blank is first subjected to pressure between a stationary head or die and a movable plunger or former forming a cooperative die element, these two members serving to bend the blank horizontally, after which the blank is forced by a vertically-reciprocatery Serial No. 150,034. (N0 model.)

plunger into a removable former, which may be taken through the machine and serves to hold a properly-shaped blank in its bent position until thoroughly dry. The strain on the wooden blank underthe action of the members for forming the horizontal bends is quite severe, and there is a tendency to breaking or splintering of the fiber on the outside of the bend, to obviate which I have employed a flexible jacket comprising two members disposed, respectively, in front and in rear of the blank and movable therewith during the formation of the horizontal bends, in addition to which j acket there is provided positively-operating mechanism to exert end pressure on the blank, thereby to prevent tearing or breakand in machines constructed in accordancewith said patent it becomes necessary to employ a counterweight or counter-spring for nullifying this movement of the band-engaging spring, thus adding to the expense of construction of the machine. To overcome this objection, the machine is now so constructed as to permit the action of the springs on the protective bands only, the end-compression arms being left free to be brought into play in a predetermined time after the bands have properly engaged with and gripped the blank. In other respects the machine remains the same as that illustrated and described in'the Letters Patent, and reference is made thereto for details of construction which it has been thought unnecessary to fully describe in the present case.

19 designates the fixed former or head, disposed at the rear end of the machine and containing all of the horizontal bends of the snath, and coacting therewith is a movable plunger or former 5, the forward face of which is curved to conform to said horizontal bends.

The plunger 5 is reciprocated by means of a suitable toggle mechanism, aportion of which is illustrated at 6, and said plunger is provided with suitable guides, at the top of the fixed frame of the machine in order to keep it in proper position.

In the operationof imparting the horizontal bend to the blank it is essential that the blank be shielded against any tendency to splintering or breaking and at the same time that end pressure be progressively applied to the butt and tap of the blank in order to effect compression thereof, and thereby obviate any tendency of the fibers on the outer side of the bends from being unduly stretched or from breaking. The means for eifecting these results comprise a flexible jacket consisting of two strips or hands of metal 20 and 21. The band 20 and band 21 are spaced apart for a sufficient distance to accommodate a blank of the desired diameter and at their opposite ends are united to yoke-shaped clips 22, preferably by bending the end portions of the bands around the vertical arms of the yokes and thence riveting or otherwise securing said bent end portions to the bands proper. To the opposite ends of the stationary former or head are secured leaf-springs 32 and 33, said springs being built up of a plurality of layers in the usual manner and having their thicker or butt ends rigidly secured to the ends of the head by suitable bolts or similar securing devices. The thinner or smaller ends of these springs extend in a forward direction to a point beyond 'the bending face of the former and are passed through the yokes 22, hearing against cross-bars 34, which are adapted to the threaded ends of said yokes, and on said threaded ends are suitable nuts 35, which may be turned to adjust the stress of the springs to any desired extent. The springs act on the strips of metal in the same manner and for the same purpose as contemplated in said Letters Patent, yielding during the bending movement in order to permit the bands to accommodate themselves to the curvature of the forming-dies and thence reassuming straight parallel positions to permit the ready insertion of a straight blank prior to the folding operation.

Near the opposite ends of the head or former 19 are vertically-disposed bolts or rods 30, on which are pivoted levers 29 and 30, the inner and shorter arms of which are forced during the operation of the machine against the ends of the blank for the purpose of giving progressive end pressure as the horizontal'bends are being imparted thereto, and thus in a positive manner to prevent stretching of the fibers of the wood on the outside of the bends. To impart the necessary outward and inward movement to the longer arms of said levers in order first to move the shorter arms into engagement with the ends of the snath-blank, thus to compress the same, and then to move the said shorter arms laterally for engagement with a fresh blank, there is provided for the first movement an adjustable bar 37, carrying at its inner end a head 38, having its outer face concave, as at 39, to conform tovthe crest of the belly-band, and thus distribute the strain thereon to reduce danger of marring at that point, the rear portion of the head being curved or rounded and being adapted when the plunger is moved to thelimit of its forward movement to rest in a recess formed in the front face of the head. The rod 37 is made adjustable or extensible to enable it to' meet the requirements arising in bending snaths, wherein the curves of the belly-band will vary, and to effect this the rod is constructed of two sections 41 and 42, and these two sections are superposed and have their opposed faces serrated, as at 43, the member 42 being provided with a slot 44, through which passes a bolt 45, carried by the member 41, a nut 46 on the bolt serving to hold the two members at the desired ad j ustment.

The free ends of the levers 29 and 30 are slotted, as at 47, to receive the upturned end 48 of a bar 49, the other end of which projects upward through a recess 50 in the plunger, as clearly shown at 51 in Fig. 2. As the plunger moves forward the blank. by contact with the band moves the latter against the head 38 and forces the rod 37 outward and the shorter arms of the levers 29 and inward, effecting thereby end compression of the snath blank, and when the plunger has reached the limit of its forward movement and has commenced to return the end of bar 49 by. coacting with the forward wall of the slot of the plunger moves the levers 29 and 30 toward the front of the machine, thereby projecting the shorter arms of the levers outward.

The means for imparting the vertical bends to the snath-blank comprise a former 52 and a removableform 73,into which the bent blank is forced by suitable mechanism,the construction and arrangement of which are fully set forth in the Letters Patent referred to.

It will be observed that the arms or levers for eflecting end compression of the snathblank are entirely independent of the protective strips and their springs and may be operated at any time after the strips of metal have been forced into contact with and grip the blank, and thus overcomes a serious difficulty to the practical operation of the machine described in the Letters Patent, wherein the springs acted to impart end pressure to the blanks before the latter were properly held by the protective strips.

Having thus described the invention, what is claimed is 1. In a machine for bending scythe-snaths, the combination with means forimparting the horizontal bends to the blank, of flexible protective strips for inclosing the opposite sides of the blank, means for efiecting end compression of said blanks, and strip-sup and the levers. 3. In a machine for bending scythe-snaths, the combination with stationary and movable forming members, of leaf-springs secured to the opposite ends of the stationary member,

flexible protective strips for engaging the opposite sides of the blank, yoke-shaped clips secured to the opposite ends of the strips and embracing the springs, and end-compression levers pivotally connected to the stationary forming member and extending through said yoke-shaped clips.

In testimony that I claim the foregoing as my own I have hereto aflixed my signature in the presence of two witnesses.

GEORGE MERRIHUE FENN.

Witnesses:

J. Ross CoLHoUN, C. E. DOYLE. 

